期刊名称：Egyptian Journal of Pediatric Allergy and Immunology
印刷版ISSN：1687-1642
电子版ISSN：2314-8934
出版年度：2012
卷号：10
期号：2
页码：67-74
出版社：Egyptian Society of Pediatric Allergy and Immunology
摘要：Crucial to the diagnosis and effective therapy of invasivefungal infection (IFI) in the immunodeficient is the early identification of thecausative agent especially in patients who lack clinical evidence of thedisease. The standard methods for the detection of fungi in clinicalspecimens are direct microscopy and mycological culture. Microscopy oftenlacks a satisfactory sensitivity, whereas diagnosis by mycological cultureoften requires a long growth period. Studies have demonstrated thefeasibility of detecting molds and yeast in a single reaction using theuniversal fungal primer. Objective: Evaluation of the role of real-time PCRin the early detection of fungal infection in immunodeficient patients withsuspected IFI, who lack clinical evidence of the disease. Methods: Thisstudy included 30 immunodeficiency patients suspected of having IFI; 9 withprimary and 21 with secondary immunodeficiency. All patients had at leastone host factor, but no clinical criteria according to the EORTC-MSGdefinition of IFI. Twenty seven had fever and 3 had bronchopneumonia, bothnot responding to broad spectrum antibiotics for 96 hrs. or more. Bloodsamples were cultured for fungi and were analyzed with real-time PCRusing universal fungal primers. For positive samples of fungal infection,aspergillus-specific primers were used for detection of aspergillus. Results:Seventeen patients (56.7%) proved to have IFI. Blood culture detectedCandida in 2 patients only, while PCR detected Candida in another 9 andAspergillus in 6, thus 15/17 patients with IFI (88%) were missed by bloodculture. Blood culture for IFI diagnosis had a very low sensitivity (12%) buthad a 100% specificity and positive predictive value. The results PCR didnot vary with gender, degree of fever, immunodeficiency type, clinicalpresentation or current intake of antifungal treatment. Patients with provenIFI showed significantly increased CRP levels as compared to those withoutinfection. Conclusion: Real-time PCR proved superior to culture in earlydiagnosis of IFI in patients with immunodeficiency before the appearance ofthe characteristic clinical and imaging signs. Reliance on blood culturealone at that stage would result in missing most of the positive cases withconsequent delay in the initiation of specific treatment
